The use of electrical pulse compression circuits to create high voltage, high current, short duration electrical pulses for use with gas discharge lasers has been well described.
The design of a pulse power system to drive a gas discharge laser is difficult due to the time varying impedance of the load. As the laser gas between the electrodes of a transverse discharge pumped laser undergoes electron avalanche, the current carrier density between the electrodes increases many orders of magnitude on a time scale between 10 ns to 100 ns. This increase in carrier density causes the gas impedance to decrease many orders of magnitude. Illustratively, discharge impedances can range from megohms when nonconducting to 0.1 ohm when fully conducting. Typical electrical drive circuits can efficiently couple power into fixed load impedances only, and thus exhibit poor coupling efficiency into a time varying impedance encountered in a gas discharge laser. A consequence of this poor coupling efficiency is current reversal in the gas discharge, leading to erosion and damage of the electrodes, wasted energy in the discharge after the lasing and optical properties of the gas have degraded, and unwanted reflection of energy into the pulse power system.
Specialized pulse power systems have been developed to improve the power coupling into gas discharge lasers. An example of such a system is a "spiker/sustainer". A spiker/sustainer comprises two separate pulse power systems, one optimized for coupling to the initially high impedance of the gas discharge and the other optimized for coupling into the subsequent lower impedance of the gas discharge. Such systems are complicated, unreliable, and expensive to manufacture.
Accordingly the art needs a reliable, uncomplicated pulse power system, that more efficiently couples pulse energy into a time-varying impedance of a gas discharge with minimal current reversal and electrode erosion.